Medical devices can be used to manipulate material lodged or disposed in a body opening, cavity, tract, or tissue directly or through an endoscope. One such routinely used medical device has an object engaging unit such as a basket, and a coupler such as a cannula that is traditionally made from an inflexible material such as stainless steel. The coupler is disposed at the base of the object engaging unit and couples the object engaging unit to other components in the medical device. Typically, the object engaging unit and the coupler are moveable relative to an overlaying sheath, from a collapsed position within the sheath to an expanded position in which the object engaging unit and the coupler extend past the distal end of the sheath. In the expanded position, the object engaging unit can be positioned and is operable at least to manipulate material, such as kidney stones, in a tissue.
When the material is lodged or disposed in narrow and/or convoluted regions of tissue, it would be advantageous for the object engaging unit's lateral movement to be unlimited in order to enhance the chance of the material being engaged, captured or retrieved successfully. However, due to the inflexible coupler that is typically joined to an object engaging unit, the lateral flexing motion of the object engaging unit found in standard medical devices is limited. Because the standard object engaging unit cannot easily make discrete lateral movements which are independent in part from the whole coupler, any lateral movement of the object engaging unit per se requires generous operating space within a tissue or body opening. Such a limitation on the movement of an object engaging unit is detrimental to the object engaging unit's ability to operate successfully in narrow and/or convoluted configurations in a tissue or body opening.